There are many techniques which can be utilized for light intensity, direction modulation, phase modulation, optical switching, optical logic, etc., which may include (but are not limited to): electro-optical methods, liquid crystals, acousto-optics, non-linear optics methods, magneto-optics, etc. There are many technologies suitable for use in display panel applications, e.g., the most typical being LCDs (liquid crystal displays). The U.S. Pat. No. 5,659,330 “Electrocapillary Color Display Sheet” by N. K. Sheridon describes another method for displays which uses electro-wetting to control the shape of dyed liquid droplets that are placed inside a capillary sheet. The display requires a large number of separate liquid droplets to be created and maintained rigidly in an array formation, which might not be possible in practical applications. Also, light modulation mechanism in the above reference (U.S. Pat. No. 5,659,330) requires the shape of the droplets to be varied macroscopically, which limits the achievable refresh rate of the display.
Another US patent application No. 2004/0109234 “Electrically Tunable Diffractive Grating Element” by T. Levola describes a deformable diffractive grating structure, where a preformed, basic surface relief of the grating is composed of dielectric and deformable viscoelastic material, which can be electrically tuned in shape to adjust the diffraction properties of the grating.